The new rule is spelled out in a recent open letter to the diocese from Bishop Dorsey McConnell, the Pittsburgh Post-Gazette reported Aug. 5.

McConnell has expressed reservations about the theology behind the church’s marriage rite, which the bishop approved for use in the diocese in November. That was before a federal judge in central Pennsylvania in May struck down the state’s law defining marriage as the union of one man and one woman, effectively making same-sex marriage legal in the state.

Diocesan spokesman Rich Creehan said the latest move isn’t an across-the-board endorsement of same-sex marriage by the diocese, and doesn’t mark a change in church teaching or the bishop’s position. It merely gives clergy who choose to marry same-sex couples the power to issue legally binding marriage certificates.

“I know and treasure the theological diversity of this diocese, and know that practice in this matter will vary from parish to parish,” McConnell wrote in the recent diocesan letter.

In approving the same-sex marriage rite for use in the diocese last year, McConnell did not order diocesan priests to perform same-sex marriages, but simply gave them the option to perform them if their conscience dictated.

The Episcopal Church approved a provisional rite for same-sex couples at its General Convention last year, subject to approval by local bishops. The measure will be reviewed at its next convention in 2015. The ceremony includes prayers and an exchange of vows and rings and the church requires same-sex couples to complete counseling before having their unions blessed.

The Episcopal Diocese of Pittsburgh has 37 congregations with about 9,100 members. A majority of its clergy and lay leaders voted to leave the diocese in 2008 and sided with more conservative churches in the global Anglican Communion in a debate that grew out of the national church’s decision to consecrate its first openly gay bishop, V. Gene Robinson of New Hampshire, in 2003.

Before the 2008 split, the Episcopal Diocese claimed 74 congregations, but because some churches also split over joining the more conservative Anglican Diocese of Pittsburgh, that diocese claims more than 50 southwestern Pennsylvania congregations, according to its website.